net/smc/smc_llc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
   4  *
   5  *  Link Layer Control (LLC)
   6  *
   7  *  Copyright IBM Corp. 2016
   8  *
   9  *  Author(s):  Klaus Wacker <[email protected]>
  10  *              Ursula Braun <[email protected]>
  11  */
  12
  13 #include <net/tcp.h>
  14 #include <rdma/ib_verbs.h>
  15
  16 #include "smc.h"
  17 #include "smc_core.h"
  18 #include "smc_clc.h"
  19 #include "smc_llc.h"
  20 #include "smc_pnet.h"
  21
  22 #define SMC_LLC_DATA_LEN                40
  23
  24 struct smc_llc_hdr {
  25         struct smc_wr_rx_hdr common;
  26         u8 length;      /* 44 */
  27 #if defined(__BIG_ENDIAN_BITFIELD)
  28         u8 reserved:4,
  29            add_link_rej_rsn:4;
  30 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  31         u8 add_link_rej_rsn:4,
  32            reserved:4;
  33 #endif
  34         u8 flags;
  35 };
  36
  37 #define SMC_LLC_FLAG_NO_RMBE_EYEC       0x03
  38
  39 struct smc_llc_msg_confirm_link {       /* type 0x01 */
  40         struct smc_llc_hdr hd;
  41         u8 sender_mac[ETH_ALEN];
  42         u8 sender_gid[SMC_GID_SIZE];
  43         u8 sender_qp_num[3];
  44         u8 link_num;
  45         u8 link_uid[SMC_LGR_ID_SIZE];
  46         u8 max_links;
  47         u8 reserved[9];
  48 };
  49
  50 #define SMC_LLC_FLAG_ADD_LNK_REJ        0x40
  51 #define SMC_LLC_REJ_RSN_NO_ALT_PATH     1
  52
  53 #define SMC_LLC_ADD_LNK_MAX_LINKS       2
  54
  55 struct smc_llc_msg_add_link {           /* type 0x02 */
  56         struct smc_llc_hdr hd;
  57         u8 sender_mac[ETH_ALEN];
  58         u8 reserved2[2];
  59         u8 sender_gid[SMC_GID_SIZE];
  60         u8 sender_qp_num[3];
  61         u8 link_num;
  62 #if defined(__BIG_ENDIAN_BITFIELD)
  63         u8 reserved3 : 4,
  64            qp_mtu   : 4;
  65 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  66         u8 qp_mtu   : 4,
  67            reserved3 : 4;
  68 #endif
  69         u8 initial_psn[3];
  70         u8 reserved[8];
  71 };
  72
  73 struct smc_llc_msg_add_link_cont_rt {
  74         __be32 rmb_key;
  75         __be32 rmb_key_new;
  76         __be64 rmb_vaddr_new;
  77 };
  78
  79 #define SMC_LLC_RKEYS_PER_CONT_MSG      2
  80
  81 struct smc_llc_msg_add_link_cont {      /* type 0x03 */
  82         struct smc_llc_hdr hd;
  83         u8 link_num;
  84         u8 num_rkeys;
  85         u8 reserved2[2];
  86         struct smc_llc_msg_add_link_cont_rt rt[SMC_LLC_RKEYS_PER_CONT_MSG];
  87         u8 reserved[4];
  88 } __packed;                     /* format defined in RFC7609 */
  89
  90 #define SMC_LLC_FLAG_DEL_LINK_ALL       0x40
  91 #define SMC_LLC_FLAG_DEL_LINK_ORDERLY   0x20
  92
  93 struct smc_llc_msg_del_link {           /* type 0x04 */
  94         struct smc_llc_hdr hd;
  95         u8 link_num;
  96         __be32 reason;
  97         u8 reserved[35];
  98 } __packed;                     /* format defined in RFC7609 */
  99
 100 struct smc_llc_msg_test_link {          /* type 0x07 */
 101         struct smc_llc_hdr hd;
 102         u8 user_data[16];
 103         u8 reserved[24];
 104 };
 105
 106 struct smc_rmb_rtoken {
 107         union {
 108                 u8 num_rkeys;   /* first rtoken byte of CONFIRM LINK msg */
 109                                 /* is actually the num of rtokens, first */
 110                                 /* rtoken is always for the current link */
 111                 u8 link_id;     /* link id of the rtoken */
 112         };
 113         __be32 rmb_key;
 114         __be64 rmb_vaddr;
 115 } __packed;                     /* format defined in RFC7609 */
 116
 117 #define SMC_LLC_RKEYS_PER_MSG   3
 118
 119 struct smc_llc_msg_confirm_rkey {       /* type 0x06 */
 120         struct smc_llc_hdr hd;
 121         struct smc_rmb_rtoken rtoken[SMC_LLC_RKEYS_PER_MSG];
 122         u8 reserved;
 123 };
 124
 125 #define SMC_LLC_DEL_RKEY_MAX    8
 126 #define SMC_LLC_FLAG_RKEY_RETRY 0x10
 127 #define SMC_LLC_FLAG_RKEY_NEG   0x20
 128
 129 struct smc_llc_msg_delete_rkey {        /* type 0x09 */
 130         struct smc_llc_hdr hd;
 131         u8 num_rkeys;
 132         u8 err_mask;
 133         u8 reserved[2];
 134         __be32 rkey[8];
 135         u8 reserved2[4];
 136 };
 137
 138 union smc_llc_msg {
 139         struct smc_llc_msg_confirm_link confirm_link;
 140         struct smc_llc_msg_add_link add_link;
 141         struct smc_llc_msg_add_link_cont add_link_cont;
 142         struct smc_llc_msg_del_link delete_link;
 143
 144         struct smc_llc_msg_confirm_rkey confirm_rkey;
 145         struct smc_llc_msg_delete_rkey delete_rkey;
 146
 147         struct smc_llc_msg_test_link test_link;
 148         struct {
 149                 struct smc_llc_hdr hdr;
 150                 u8 data[SMC_LLC_DATA_LEN];
 151         } raw;
 152 };
 153
 154 #define SMC_LLC_FLAG_RESP               0x80
 155
 156 struct smc_llc_qentry {
 157         struct list_head list;
 158         struct smc_link *link;
 159         union smc_llc_msg msg;
 160 };
 161
 162 static void smc_llc_enqueue(struct smc_link *link, union smc_llc_msg *llc);
 163
 164 struct smc_llc_qentry *smc_llc_flow_qentry_clr(struct smc_llc_flow *flow)
 165 {
 166         struct smc_llc_qentry *qentry = flow->qentry;
 167
 168         flow->qentry = NULL;
 169         return qentry;
 170 }
 171
 172 void smc_llc_flow_qentry_del(struct smc_llc_flow *flow)
 173 {
 174         struct smc_llc_qentry *qentry;
 175
 176         if (flow->qentry) {
 177                 qentry = flow->qentry;
 178                 flow->qentry = NULL;
 179                 kfree(qentry);
 180         }
 181 }
 182
 183 static inline void smc_llc_flow_qentry_set(struct smc_llc_flow *flow,
 184                                            struct smc_llc_qentry *qentry)
 185 {
 186         flow->qentry = qentry;
 187 }
 188
 189 static void smc_llc_flow_parallel(struct smc_link_group *lgr, u8 flow_type,
 190                                   struct smc_llc_qentry *qentry)
 191 {
 192         u8 msg_type = qentry->msg.raw.hdr.common.type;
 193
 194         if ((msg_type == SMC_LLC_ADD_LINK || msg_type == SMC_LLC_DELETE_LINK) &&
 195             flow_type != msg_type && !lgr->delayed_event) {
 196                 lgr->delayed_event = qentry;
 197                 return;
 198         }
 199         /* drop parallel or already-in-progress llc requests */
 200         if (flow_type != msg_type)
 201                 pr_warn_once("smc: SMC-R lg %*phN dropped parallel "
 202                              "LLC msg: msg %d flow %d role %d\n",
 203                              SMC_LGR_ID_SIZE, &lgr->id,
 204                              qentry->msg.raw.hdr.common.type,
 205                              flow_type, lgr->role);
 206         kfree(qentry);
 207 }
 208
 209 /* try to start a new llc flow, initiated by an incoming llc msg */
 210 static bool smc_llc_flow_start(struct smc_llc_flow *flow,
 211                                struct smc_llc_qentry *qentry)
 212 {
 213         struct smc_link_group *lgr = qentry->link->lgr;
 214
 215         spin_lock_bh(&lgr->llc_flow_lock);
 216         if (flow->type) {
 217                 /* a flow is already active */
 218                 smc_llc_flow_parallel(lgr, flow->type, qentry);
 219                 spin_unlock_bh(&lgr->llc_flow_lock);
 220                 return false;
 221         }
 222         switch (qentry->msg.raw.hdr.common.type) {
 223         case SMC_LLC_ADD_LINK:
 224                 flow->type = SMC_LLC_FLOW_ADD_LINK;
 225                 break;
 226         case SMC_LLC_DELETE_LINK:
 227                 flow->type = SMC_LLC_FLOW_DEL_LINK;
 228                 break;
 229         case SMC_LLC_CONFIRM_RKEY:
 230         case SMC_LLC_DELETE_RKEY:
 231                 flow->type = SMC_LLC_FLOW_RKEY;
 232                 break;
 233         default:
 234                 flow->type = SMC_LLC_FLOW_NONE;
 235         }
 236         smc_llc_flow_qentry_set(flow, qentry);
 237         spin_unlock_bh(&lgr->llc_flow_lock);
 238         return true;
 239 }
 240
 241 /* start a new local llc flow, wait till current flow finished */
 242 int smc_llc_flow_initiate(struct smc_link_group *lgr,
 243                           enum smc_llc_flowtype type)
 244 {
 245         enum smc_llc_flowtype allowed_remote = SMC_LLC_FLOW_NONE;
 246         int rc;
 247
 248         /* all flows except confirm_rkey and delete_rkey are exclusive,
 249          * confirm/delete rkey flows can run concurrently (local and remote)
 250          */
 251         if (type == SMC_LLC_FLOW_RKEY)
 252                 allowed_remote = SMC_LLC_FLOW_RKEY;
 253 again:
 254         if (list_empty(&lgr->list))
 255                 return -ENODEV;
 256         spin_lock_bh(&lgr->llc_flow_lock);
 257         if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE &&
 258             (lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE ||
 259              lgr->llc_flow_rmt.type == allowed_remote)) {
 260                 lgr->llc_flow_lcl.type = type;
 261                 spin_unlock_bh(&lgr->llc_flow_lock);
 262                 return 0;
 263         }
 264         spin_unlock_bh(&lgr->llc_flow_lock);
 265         rc = wait_event_timeout(lgr->llc_flow_waiter, (list_empty(&lgr->list) ||
 266                                 (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_NONE &&
 267                                  (lgr->llc_flow_rmt.type == SMC_LLC_FLOW_NONE ||
 268                                   lgr->llc_flow_rmt.type == allowed_remote))),
 269                                 SMC_LLC_WAIT_TIME * 10);
 270         if (!rc)
 271                 return -ETIMEDOUT;
 272         goto again;
 273 }
 274
 275 /* finish the current llc flow */
 276 void smc_llc_flow_stop(struct smc_link_group *lgr, struct smc_llc_flow *flow)
 277 {
 278         spin_lock_bh(&lgr->llc_flow_lock);
 279         memset(flow, 0, sizeof(*flow));
 280         flow->type = SMC_LLC_FLOW_NONE;
 281         spin_unlock_bh(&lgr->llc_flow_lock);
 282         if (!list_empty(&lgr->list) && lgr->delayed_event &&
 283             flow == &lgr->llc_flow_lcl)
 284                 schedule_work(&lgr->llc_event_work);
 285         else
 286                 wake_up(&lgr->llc_flow_waiter);
 287 }
 288
 289 /* lnk is optional and used for early wakeup when link goes down, useful in
 290  * cases where we wait for a response on the link after we sent a request
 291  */
 292 struct smc_llc_qentry *smc_llc_wait(struct smc_link_group *lgr,
 293                                     struct smc_link *lnk,
 294                                     int time_out, u8 exp_msg)
 295 {
 296         struct smc_llc_flow *flow = &lgr->llc_flow_lcl;
 297         u8 rcv_msg;
 298
 299         wait_event_timeout(lgr->llc_msg_waiter,
 300                            (flow->qentry ||
 301                             (lnk && !smc_link_usable(lnk)) ||
 302                             list_empty(&lgr->list)),
 303                            time_out);
 304         if (!flow->qentry ||
 305             (lnk && !smc_link_usable(lnk)) || list_empty(&lgr->list)) {
 306                 smc_llc_flow_qentry_del(flow);
 307                 goto out;
 308         }
 309         rcv_msg = flow->qentry->msg.raw.hdr.common.type;
 310         if (exp_msg && rcv_msg != exp_msg) {
 311                 if (exp_msg == SMC_LLC_ADD_LINK &&
 312                     rcv_msg == SMC_LLC_DELETE_LINK) {
 313                         /* flow_start will delay the unexpected msg */
 314                         smc_llc_flow_start(&lgr->llc_flow_lcl,
 315                                            smc_llc_flow_qentry_clr(flow));
 316                         return NULL;
 317                 }
 318                 pr_warn_once("smc: SMC-R lg %*phN dropped unexpected LLC msg: "
 319                              "msg %d exp %d flow %d role %d flags %x\n",
 320                              SMC_LGR_ID_SIZE, &lgr->id, rcv_msg, exp_msg,
 321                              flow->type, lgr->role,
 322                              flow->qentry->msg.raw.hdr.flags);
 323                 smc_llc_flow_qentry_del(flow);
 324         }
 325 out:
 326         return flow->qentry;
 327 }
 328
 329 /********************************** send *************************************/
 330
 331 struct smc_llc_tx_pend {
 332 };
 333
 334 /* handler for send/transmission completion of an LLC msg */
 335 static void smc_llc_tx_handler(struct smc_wr_tx_pend_priv *pend,
 336                                struct smc_link *link,
 337                                enum ib_wc_status wc_status)
 338 {
 339         /* future work: handle wc_status error for recovery and failover */
 340 }
 341
 342 /**
 343  * smc_llc_add_pending_send() - add LLC control message to pending WQE transmits
 344  * @link: Pointer to SMC link used for sending LLC control message.
 345  * @wr_buf: Out variable returning pointer to work request payload buffer.
 346  * @pend: Out variable returning pointer to private pending WR tracking.
 347  *        It's the context the transmit complete handler will get.
 348  *
 349  * Reserves and pre-fills an entry for a pending work request send/tx.
 350  * Used by mid-level smc_llc_send_msg() to prepare for later actual send/tx.
 351  * Can sleep due to smc_get_ctrl_buf (if not in softirq context).
 352  *
 353  * Return: 0 on success, otherwise an error value.
 354  */
 355 static int smc_llc_add_pending_send(struct smc_link *link,
 356                                     struct smc_wr_buf **wr_buf,
 357                                     struct smc_wr_tx_pend_priv **pend)
 358 {
 359         int rc;
 360
 361         rc = smc_wr_tx_get_free_slot(link, smc_llc_tx_handler, wr_buf, NULL,
 362                                      pend);
 363         if (rc < 0)
 364                 return rc;
 365         BUILD_BUG_ON_MSG(
 366                 sizeof(union smc_llc_msg) > SMC_WR_BUF_SIZE,
 367                 "must increase SMC_WR_BUF_SIZE to at least sizeof(struct smc_llc_msg)");
 368         BUILD_BUG_ON_MSG(
 369                 sizeof(union smc_llc_msg) != SMC_WR_TX_SIZE,
 370                 "must adapt SMC_WR_TX_SIZE to sizeof(struct smc_llc_msg); if not all smc_wr upper layer protocols use the same message size any more, must start to set link->wr_tx_sges[i].length on each individual smc_wr_tx_send()");
 371         BUILD_BUG_ON_MSG(
 372                 sizeof(struct smc_llc_tx_pend) > SMC_WR_TX_PEND_PRIV_SIZE,
 373                 "must increase SMC_WR_TX_PEND_PRIV_SIZE to at least sizeof(struct smc_llc_tx_pend)");
 374         return 0;
 375 }
 376
 377 /* high-level API to send LLC confirm link */
 378 int smc_llc_send_confirm_link(struct smc_link *link,
 379                               enum smc_llc_reqresp reqresp)
 380 {
 381         struct smc_llc_msg_confirm_link *confllc;
 382         struct smc_wr_tx_pend_priv *pend;
 383         struct smc_wr_buf *wr_buf;
 384         int rc;
 385
 386         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 387         if (rc)
 388                 return rc;
 389         confllc = (struct smc_llc_msg_confirm_link *)wr_buf;
 390         memset(confllc, 0, sizeof(*confllc));
 391         confllc->hd.common.type = SMC_LLC_CONFIRM_LINK;
 392         confllc->hd.length = sizeof(struct smc_llc_msg_confirm_link);
 393         confllc->hd.flags |= SMC_LLC_FLAG_NO_RMBE_EYEC;
 394         if (reqresp == SMC_LLC_RESP)
 395                 confllc->hd.flags |= SMC_LLC_FLAG_RESP;
 396         memcpy(confllc->sender_mac, link->smcibdev->mac[link->ibport - 1],
 397                ETH_ALEN);
 398         memcpy(confllc->sender_gid, link->gid, SMC_GID_SIZE);
 399         hton24(confllc->sender_qp_num, link->roce_qp->qp_num);
 400         confllc->link_num = link->link_id;
 401         memcpy(confllc->link_uid, link->link_uid, SMC_LGR_ID_SIZE);
 402         confllc->max_links = SMC_LLC_ADD_LNK_MAX_LINKS;
 403         /* send llc message */
 404         rc = smc_wr_tx_send(link, pend);
 405         return rc;
 406 }
 407
 408 /* send LLC confirm rkey request */
 409 static int smc_llc_send_confirm_rkey(struct smc_link *send_link,
 410                                      struct smc_buf_desc *rmb_desc)
 411 {
 412         struct smc_llc_msg_confirm_rkey *rkeyllc;
 413         struct smc_wr_tx_pend_priv *pend;
 414         struct smc_wr_buf *wr_buf;
 415         struct smc_link *link;
 416         int i, rc, rtok_ix;
 417
 418         rc = smc_llc_add_pending_send(send_link, &wr_buf, &pend);
 419         if (rc)
 420                 return rc;
 421         rkeyllc = (struct smc_llc_msg_confirm_rkey *)wr_buf;
 422         memset(rkeyllc, 0, sizeof(*rkeyllc));
 423         rkeyllc->hd.common.type = SMC_LLC_CONFIRM_RKEY;
 424         rkeyllc->hd.length = sizeof(struct smc_llc_msg_confirm_rkey);
 425
 426         rtok_ix = 1;
 427         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 428                 link = &send_link->lgr->lnk[i];
 429                 if (smc_link_active(link) && link != send_link) {
 430                         rkeyllc->rtoken[rtok_ix].link_id = link->link_id;
 431                         rkeyllc->rtoken[rtok_ix].rmb_key =
 432                                 htonl(rmb_desc->mr_rx[link->link_idx]->rkey);
 433                         rkeyllc->rtoken[rtok_ix].rmb_vaddr = cpu_to_be64(
 434                                 (u64)sg_dma_address(
 435                                         rmb_desc->sgt[link->link_idx].sgl));
 436                         rtok_ix++;
 437                 }
 438         }
 439         /* rkey of send_link is in rtoken[0] */
 440         rkeyllc->rtoken[0].num_rkeys = rtok_ix - 1;
 441         rkeyllc->rtoken[0].rmb_key =
 442                 htonl(rmb_desc->mr_rx[send_link->link_idx]->rkey);
 443         rkeyllc->rtoken[0].rmb_vaddr = cpu_to_be64(
 444                 (u64)sg_dma_address(rmb_desc->sgt[send_link->link_idx].sgl));
 445         /* send llc message */
 446         rc = smc_wr_tx_send(send_link, pend);
 447         return rc;
 448 }
 449
 450 /* send LLC delete rkey request */
 451 static int smc_llc_send_delete_rkey(struct smc_link *link,
 452                                     struct smc_buf_desc *rmb_desc)
 453 {
 454         struct smc_llc_msg_delete_rkey *rkeyllc;
 455         struct smc_wr_tx_pend_priv *pend;
 456         struct smc_wr_buf *wr_buf;
 457         int rc;
 458
 459         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 460         if (rc)
 461                 return rc;
 462         rkeyllc = (struct smc_llc_msg_delete_rkey *)wr_buf;
 463         memset(rkeyllc, 0, sizeof(*rkeyllc));
 464         rkeyllc->hd.common.type = SMC_LLC_DELETE_RKEY;
 465         rkeyllc->hd.length = sizeof(struct smc_llc_msg_delete_rkey);
 466         rkeyllc->num_rkeys = 1;
 467         rkeyllc->rkey[0] = htonl(rmb_desc->mr_rx[link->link_idx]->rkey);
 468         /* send llc message */
 469         rc = smc_wr_tx_send(link, pend);
 470         return rc;
 471 }
 472
 473 /* send ADD LINK request or response */
 474 int smc_llc_send_add_link(struct smc_link *link, u8 mac[], u8 gid[],
 475                           struct smc_link *link_new,
 476                           enum smc_llc_reqresp reqresp)
 477 {
 478         struct smc_llc_msg_add_link *addllc;
 479         struct smc_wr_tx_pend_priv *pend;
 480         struct smc_wr_buf *wr_buf;
 481         int rc;
 482
 483         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 484         if (rc)
 485                 return rc;
 486         addllc = (struct smc_llc_msg_add_link *)wr_buf;
 487
 488         memset(addllc, 0, sizeof(*addllc));
 489         addllc->hd.common.type = SMC_LLC_ADD_LINK;
 490         addllc->hd.length = sizeof(struct smc_llc_msg_add_link);
 491         if (reqresp == SMC_LLC_RESP)
 492                 addllc->hd.flags |= SMC_LLC_FLAG_RESP;
 493         memcpy(addllc->sender_mac, mac, ETH_ALEN);
 494         memcpy(addllc->sender_gid, gid, SMC_GID_SIZE);
 495         if (link_new) {
 496                 addllc->link_num = link_new->link_id;
 497                 hton24(addllc->sender_qp_num, link_new->roce_qp->qp_num);
 498                 hton24(addllc->initial_psn, link_new->psn_initial);
 499                 if (reqresp == SMC_LLC_REQ)
 500                         addllc->qp_mtu = link_new->path_mtu;
 501                 else
 502                         addllc->qp_mtu = min(link_new->path_mtu,
 503                                              link_new->peer_mtu);
 504         }
 505         /* send llc message */
 506         rc = smc_wr_tx_send(link, pend);
 507         return rc;
 508 }
 509
 510 /* send DELETE LINK request or response */
 511 int smc_llc_send_delete_link(struct smc_link *link, u8 link_del_id,
 512                              enum smc_llc_reqresp reqresp, bool orderly,
 513                              u32 reason)
 514 {
 515         struct smc_llc_msg_del_link *delllc;
 516         struct smc_wr_tx_pend_priv *pend;
 517         struct smc_wr_buf *wr_buf;
 518         int rc;
 519
 520         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 521         if (rc)
 522                 return rc;
 523         delllc = (struct smc_llc_msg_del_link *)wr_buf;
 524
 525         memset(delllc, 0, sizeof(*delllc));
 526         delllc->hd.common.type = SMC_LLC_DELETE_LINK;
 527         delllc->hd.length = sizeof(struct smc_llc_msg_del_link);
 528         if (reqresp == SMC_LLC_RESP)
 529                 delllc->hd.flags |= SMC_LLC_FLAG_RESP;
 530         if (orderly)
 531                 delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
 532         if (link_del_id)
 533                 delllc->link_num = link_del_id;
 534         else
 535                 delllc->hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
 536         delllc->reason = htonl(reason);
 537         /* send llc message */
 538         rc = smc_wr_tx_send(link, pend);
 539         return rc;
 540 }
 541
 542 /* send LLC test link request */
 543 static int smc_llc_send_test_link(struct smc_link *link, u8 user_data[16])
 544 {
 545         struct smc_llc_msg_test_link *testllc;
 546         struct smc_wr_tx_pend_priv *pend;
 547         struct smc_wr_buf *wr_buf;
 548         int rc;
 549
 550         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 551         if (rc)
 552                 return rc;
 553         testllc = (struct smc_llc_msg_test_link *)wr_buf;
 554         memset(testllc, 0, sizeof(*testllc));
 555         testllc->hd.common.type = SMC_LLC_TEST_LINK;
 556         testllc->hd.length = sizeof(struct smc_llc_msg_test_link);
 557         memcpy(testllc->user_data, user_data, sizeof(testllc->user_data));
 558         /* send llc message */
 559         rc = smc_wr_tx_send(link, pend);
 560         return rc;
 561 }
 562
 563 /* schedule an llc send on link, may wait for buffers */
 564 static int smc_llc_send_message(struct smc_link *link, void *llcbuf)
 565 {
 566         struct smc_wr_tx_pend_priv *pend;
 567         struct smc_wr_buf *wr_buf;
 568         int rc;
 569
 570         if (!smc_link_usable(link))
 571                 return -ENOLINK;
 572         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 573         if (rc)
 574                 return rc;
 575         memcpy(wr_buf, llcbuf, sizeof(union smc_llc_msg));
 576         return smc_wr_tx_send(link, pend);
 577 }
 578
 579 /* schedule an llc send on link, may wait for buffers,
 580  * and wait for send completion notification.
 581  * @return 0 on success
 582  */
 583 static int smc_llc_send_message_wait(struct smc_link *link, void *llcbuf)
 584 {
 585         struct smc_wr_tx_pend_priv *pend;
 586         struct smc_wr_buf *wr_buf;
 587         int rc;
 588
 589         if (!smc_link_usable(link))
 590                 return -ENOLINK;
 591         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 592         if (rc)
 593                 return rc;
 594         memcpy(wr_buf, llcbuf, sizeof(union smc_llc_msg));
 595         return smc_wr_tx_send_wait(link, pend, SMC_LLC_WAIT_TIME);
 596 }
 597
 598 /********************************* receive ***********************************/
 599
 600 static int smc_llc_alloc_alt_link(struct smc_link_group *lgr,
 601                                   enum smc_lgr_type lgr_new_t)
 602 {
 603         int i;
 604
 605         if (lgr->type == SMC_LGR_SYMMETRIC ||
 606             (lgr->type != SMC_LGR_SINGLE &&
 607              (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
 608               lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)))
 609                 return -EMLINK;
 610
 611         if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
 612             lgr_new_t == SMC_LGR_ASYMMETRIC_PEER) {
 613                 for (i = SMC_LINKS_PER_LGR_MAX - 1; i >= 0; i--)
 614                         if (lgr->lnk[i].state == SMC_LNK_UNUSED)
 615                                 return i;
 616         } else {
 617                 for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++)
 618                         if (lgr->lnk[i].state == SMC_LNK_UNUSED)
 619                                 return i;
 620         }
 621         return -EMLINK;
 622 }
 623
 624 /* return first buffer from any of the next buf lists */
 625 static struct smc_buf_desc *_smc_llc_get_next_rmb(struct smc_link_group *lgr,
 626                                                   int *buf_lst)
 627 {
 628         struct smc_buf_desc *buf_pos;
 629
 630         while (*buf_lst < SMC_RMBE_SIZES) {
 631                 buf_pos = list_first_entry_or_null(&lgr->rmbs[*buf_lst],
 632                                                    struct smc_buf_desc, list);
 633                 if (buf_pos)
 634                         return buf_pos;
 635                 (*buf_lst)++;
 636         }
 637         return NULL;
 638 }
 639
 640 /* return next rmb from buffer lists */
 641 static struct smc_buf_desc *smc_llc_get_next_rmb(struct smc_link_group *lgr,
 642                                                  int *buf_lst,
 643                                                  struct smc_buf_desc *buf_pos)
 644 {
 645         struct smc_buf_desc *buf_next;
 646
 647         if (!buf_pos || list_is_last(&buf_pos->list, &lgr->rmbs[*buf_lst])) {
 648                 (*buf_lst)++;
 649                 return _smc_llc_get_next_rmb(lgr, buf_lst);
 650         }
 651         buf_next = list_next_entry(buf_pos, list);
 652         return buf_next;
 653 }
 654
 655 static struct smc_buf_desc *smc_llc_get_first_rmb(struct smc_link_group *lgr,
 656                                                   int *buf_lst)
 657 {
 658         *buf_lst = 0;
 659         return smc_llc_get_next_rmb(lgr, buf_lst, NULL);
 660 }
 661
 662 /* send one add_link_continue msg */
 663 static int smc_llc_add_link_cont(struct smc_link *link,
 664                                  struct smc_link *link_new, u8 *num_rkeys_todo,
 665                                  int *buf_lst, struct smc_buf_desc **buf_pos)
 666 {
 667         struct smc_llc_msg_add_link_cont *addc_llc;
 668         struct smc_link_group *lgr = link->lgr;
 669         int prim_lnk_idx, lnk_idx, i, rc;
 670         struct smc_wr_tx_pend_priv *pend;
 671         struct smc_wr_buf *wr_buf;
 672         struct smc_buf_desc *rmb;
 673         u8 n;
 674
 675         rc = smc_llc_add_pending_send(link, &wr_buf, &pend);
 676         if (rc)
 677                 return rc;
 678         addc_llc = (struct smc_llc_msg_add_link_cont *)wr_buf;
 679         memset(addc_llc, 0, sizeof(*addc_llc));
 680
 681         prim_lnk_idx = link->link_idx;
 682         lnk_idx = link_new->link_idx;
 683         addc_llc->link_num = link_new->link_id;
 684         addc_llc->num_rkeys = *num_rkeys_todo;
 685         n = *num_rkeys_todo;
 686         for (i = 0; i < min_t(u8, n, SMC_LLC_RKEYS_PER_CONT_MSG); i++) {
 687                 if (!*buf_pos) {
 688                         addc_llc->num_rkeys = addc_llc->num_rkeys -
 689                                               *num_rkeys_todo;
 690                         *num_rkeys_todo = 0;
 691                         break;
 692                 }
 693                 rmb = *buf_pos;
 694
 695                 addc_llc->rt[i].rmb_key = htonl(rmb->mr_rx[prim_lnk_idx]->rkey);
 696                 addc_llc->rt[i].rmb_key_new = htonl(rmb->mr_rx[lnk_idx]->rkey);
 697                 addc_llc->rt[i].rmb_vaddr_new =
 698                         cpu_to_be64((u64)sg_dma_address(rmb->sgt[lnk_idx].sgl));
 699
 700                 (*num_rkeys_todo)--;
 701                 *buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
 702                 while (*buf_pos && !(*buf_pos)->used)
 703                         *buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
 704         }
 705         addc_llc->hd.common.type = SMC_LLC_ADD_LINK_CONT;
 706         addc_llc->hd.length = sizeof(struct smc_llc_msg_add_link_cont);
 707         if (lgr->role == SMC_CLNT)
 708                 addc_llc->hd.flags |= SMC_LLC_FLAG_RESP;
 709         return smc_wr_tx_send(link, pend);
 710 }
 711
 712 static int smc_llc_cli_rkey_exchange(struct smc_link *link,
 713                                      struct smc_link *link_new)
 714 {
 715         struct smc_llc_msg_add_link_cont *addc_llc;
 716         struct smc_link_group *lgr = link->lgr;
 717         u8 max, num_rkeys_send, num_rkeys_recv;
 718         struct smc_llc_qentry *qentry;
 719         struct smc_buf_desc *buf_pos;
 720         int buf_lst;
 721         int rc = 0;
 722         int i;
 723
 724         mutex_lock(&lgr->rmbs_lock);
 725         num_rkeys_send = lgr->conns_num;
 726         buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
 727         do {
 728                 qentry = smc_llc_wait(lgr, NULL, SMC_LLC_WAIT_TIME,
 729                                       SMC_LLC_ADD_LINK_CONT);
 730                 if (!qentry) {
 731                         rc = -ETIMEDOUT;
 732                         break;
 733                 }
 734                 addc_llc = &qentry->msg.add_link_cont;
 735                 num_rkeys_recv = addc_llc->num_rkeys;
 736                 max = min_t(u8, num_rkeys_recv, SMC_LLC_RKEYS_PER_CONT_MSG);
 737                 for (i = 0; i < max; i++) {
 738                         smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
 739                                        addc_llc->rt[i].rmb_key,
 740                                        addc_llc->rt[i].rmb_vaddr_new,
 741                                        addc_llc->rt[i].rmb_key_new);
 742                         num_rkeys_recv--;
 743                 }
 744                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
 745                 rc = smc_llc_add_link_cont(link, link_new, &num_rkeys_send,
 746                                            &buf_lst, &buf_pos);
 747                 if (rc)
 748                         break;
 749         } while (num_rkeys_send || num_rkeys_recv);
 750
 751         mutex_unlock(&lgr->rmbs_lock);
 752         return rc;
 753 }
 754
 755 /* prepare and send an add link reject response */
 756 static int smc_llc_cli_add_link_reject(struct smc_llc_qentry *qentry)
 757 {
 758         qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_RESP;
 759         qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_ADD_LNK_REJ;
 760         qentry->msg.raw.hdr.add_link_rej_rsn = SMC_LLC_REJ_RSN_NO_ALT_PATH;
 761         return smc_llc_send_message(qentry->link, &qentry->msg);
 762 }
 763
 764 static int smc_llc_cli_conf_link(struct smc_link *link,
 765                                  struct smc_init_info *ini,
 766                                  struct smc_link *link_new,
 767                                  enum smc_lgr_type lgr_new_t)
 768 {
 769         struct smc_link_group *lgr = link->lgr;
 770         struct smc_llc_qentry *qentry = NULL;
 771         int rc = 0;
 772
 773         /* receive CONFIRM LINK request over RoCE fabric */
 774         qentry = smc_llc_wait(lgr, NULL, SMC_LLC_WAIT_FIRST_TIME, 0);
 775         if (!qentry) {
 776                 rc = smc_llc_send_delete_link(link, link_new->link_id,
 777                                               SMC_LLC_REQ, false,
 778                                               SMC_LLC_DEL_LOST_PATH);
 779                 return -ENOLINK;
 780         }
 781         if (qentry->msg.raw.hdr.common.type != SMC_LLC_CONFIRM_LINK) {
 782                 /* received DELETE_LINK instead */
 783                 qentry->msg.raw.hdr.flags |= SMC_LLC_FLAG_RESP;
 784                 smc_llc_send_message(link, &qentry->msg);
 785                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
 786                 return -ENOLINK;
 787         }
 788         smc_llc_save_peer_uid(qentry);
 789         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
 790
 791         rc = smc_ib_modify_qp_rts(link_new);
 792         if (rc) {
 793                 smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
 794                                          false, SMC_LLC_DEL_LOST_PATH);
 795                 return -ENOLINK;
 796         }
 797         smc_wr_remember_qp_attr(link_new);
 798
 799         rc = smcr_buf_reg_lgr(link_new);
 800         if (rc) {
 801                 smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
 802                                          false, SMC_LLC_DEL_LOST_PATH);
 803                 return -ENOLINK;
 804         }
 805
 806         /* send CONFIRM LINK response over RoCE fabric */
 807         rc = smc_llc_send_confirm_link(link_new, SMC_LLC_RESP);
 808         if (rc) {
 809                 smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
 810                                          false, SMC_LLC_DEL_LOST_PATH);
 811                 return -ENOLINK;
 812         }
 813         smc_llc_link_active(link_new);
 814         if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
 815             lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)
 816                 smcr_lgr_set_type_asym(lgr, lgr_new_t, link_new->link_idx);
 817         else
 818                 smcr_lgr_set_type(lgr, lgr_new_t);
 819         return 0;
 820 }
 821
 822 static void smc_llc_save_add_link_info(struct smc_link *link,
 823                                        struct smc_llc_msg_add_link *add_llc)
 824 {
 825         link->peer_qpn = ntoh24(add_llc->sender_qp_num);
 826         memcpy(link->peer_gid, add_llc->sender_gid, SMC_GID_SIZE);
 827         memcpy(link->peer_mac, add_llc->sender_mac, ETH_ALEN);
 828         link->peer_psn = ntoh24(add_llc->initial_psn);
 829         link->peer_mtu = add_llc->qp_mtu;
 830 }
 831
 832 /* as an SMC client, process an add link request */
 833 int smc_llc_cli_add_link(struct smc_link *link, struct smc_llc_qentry *qentry)
 834 {
 835         struct smc_llc_msg_add_link *llc = &qentry->msg.add_link;
 836         enum smc_lgr_type lgr_new_t = SMC_LGR_SYMMETRIC;
 837         struct smc_link_group *lgr = smc_get_lgr(link);
 838         struct smc_link *lnk_new = NULL;
 839         struct smc_init_info ini;
 840         int lnk_idx, rc = 0;
 841
 842         if (!llc->qp_mtu)
 843                 goto out_reject;
 844
 845         ini.vlan_id = lgr->vlan_id;
 846         smc_pnet_find_alt_roce(lgr, &ini, link->smcibdev);
 847         if (!memcmp(llc->sender_gid, link->peer_gid, SMC_GID_SIZE) &&
 848             !memcmp(llc->sender_mac, link->peer_mac, ETH_ALEN)) {
 849                 if (!ini.ib_dev)
 850                         goto out_reject;
 851                 lgr_new_t = SMC_LGR_ASYMMETRIC_PEER;
 852         }
 853         if (!ini.ib_dev) {
 854                 lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
 855                 ini.ib_dev = link->smcibdev;
 856                 ini.ib_port = link->ibport;
 857         }
 858         lnk_idx = smc_llc_alloc_alt_link(lgr, lgr_new_t);
 859         if (lnk_idx < 0)
 860                 goto out_reject;
 861         lnk_new = &lgr->lnk[lnk_idx];
 862         rc = smcr_link_init(lgr, lnk_new, lnk_idx, &ini);
 863         if (rc)
 864                 goto out_reject;
 865         smc_llc_save_add_link_info(lnk_new, llc);
 866         lnk_new->link_id = llc->link_num;       /* SMC server assigns link id */
 867         smc_llc_link_set_uid(lnk_new);
 868
 869         rc = smc_ib_ready_link(lnk_new);
 870         if (rc)
 871                 goto out_clear_lnk;
 872
 873         rc = smcr_buf_map_lgr(lnk_new);
 874         if (rc)
 875                 goto out_clear_lnk;
 876
 877         rc = smc_llc_send_add_link(link,
 878                                    lnk_new->smcibdev->mac[ini.ib_port - 1],
 879                                    lnk_new->gid, lnk_new, SMC_LLC_RESP);
 880         if (rc)
 881                 goto out_clear_lnk;
 882         rc = smc_llc_cli_rkey_exchange(link, lnk_new);
 883         if (rc) {
 884                 rc = 0;
 885                 goto out_clear_lnk;
 886         }
 887         rc = smc_llc_cli_conf_link(link, &ini, lnk_new, lgr_new_t);
 888         if (!rc)
 889                 goto out;
 890 out_clear_lnk:
 891         smcr_link_clear(lnk_new, false);
 892 out_reject:
 893         smc_llc_cli_add_link_reject(qentry);
 894 out:
 895         kfree(qentry);
 896         return rc;
 897 }
 898
 899 /* as an SMC client, invite server to start the add_link processing */
 900 static void smc_llc_cli_add_link_invite(struct smc_link *link,
 901                                         struct smc_llc_qentry *qentry)
 902 {
 903         struct smc_link_group *lgr = smc_get_lgr(link);
 904         struct smc_init_info ini;
 905
 906         if (lgr->type == SMC_LGR_SYMMETRIC ||
 907             lgr->type == SMC_LGR_ASYMMETRIC_PEER)
 908                 goto out;
 909
 910         ini.vlan_id = lgr->vlan_id;
 911         smc_pnet_find_alt_roce(lgr, &ini, link->smcibdev);
 912         if (!ini.ib_dev)
 913                 goto out;
 914
 915         smc_llc_send_add_link(link, ini.ib_dev->mac[ini.ib_port - 1],
 916                               ini.ib_gid, NULL, SMC_LLC_REQ);
 917 out:
 918         kfree(qentry);
 919 }
 920
 921 static bool smc_llc_is_empty_llc_message(union smc_llc_msg *llc)
 922 {
 923         int i;
 924
 925         for (i = 0; i < ARRAY_SIZE(llc->raw.data); i++)
 926                 if (llc->raw.data[i])
 927                         return false;
 928         return true;
 929 }
 930
 931 static bool smc_llc_is_local_add_link(union smc_llc_msg *llc)
 932 {
 933         if (llc->raw.hdr.common.type == SMC_LLC_ADD_LINK &&
 934             smc_llc_is_empty_llc_message(llc))
 935                 return true;
 936         return false;
 937 }
 938
 939 static void smc_llc_process_cli_add_link(struct smc_link_group *lgr)
 940 {
 941         struct smc_llc_qentry *qentry;
 942
 943         qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
 944
 945         mutex_lock(&lgr->llc_conf_mutex);
 946         if (smc_llc_is_local_add_link(&qentry->msg))
 947                 smc_llc_cli_add_link_invite(qentry->link, qentry);
 948         else
 949                 smc_llc_cli_add_link(qentry->link, qentry);
 950         mutex_unlock(&lgr->llc_conf_mutex);
 951 }
 952
 953 static int smc_llc_active_link_count(struct smc_link_group *lgr)
 954 {
 955         int i, link_count = 0;
 956
 957         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 958                 if (!smc_link_active(&lgr->lnk[i]))
 959                         continue;
 960                 link_count++;
 961         }
 962         return link_count;
 963 }
 964
 965 /* find the asymmetric link when 3 links are established  */
 966 static struct smc_link *smc_llc_find_asym_link(struct smc_link_group *lgr)
 967 {
 968         int asym_idx = -ENOENT;
 969         int i, j, k;
 970         bool found;
 971
 972         /* determine asymmetric link */
 973         found = false;
 974         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 975                 for (j = i + 1; j < SMC_LINKS_PER_LGR_MAX; j++) {
 976                         if (!smc_link_usable(&lgr->lnk[i]) ||
 977                             !smc_link_usable(&lgr->lnk[j]))
 978                                 continue;
 979                         if (!memcmp(lgr->lnk[i].gid, lgr->lnk[j].gid,
 980                                     SMC_GID_SIZE)) {
 981                                 found = true;   /* asym_lnk is i or j */
 982                                 break;
 983                         }
 984                 }
 985                 if (found)
 986                         break;
 987         }
 988         if (!found)
 989                 goto out; /* no asymmetric link */
 990         for (k = 0; k < SMC_LINKS_PER_LGR_MAX; k++) {
 991                 if (!smc_link_usable(&lgr->lnk[k]))
 992                         continue;
 993                 if (k != i &&
 994                     !memcmp(lgr->lnk[i].peer_gid, lgr->lnk[k].peer_gid,
 995                             SMC_GID_SIZE)) {
 996                         asym_idx = i;
 997                         break;
 998                 }
 999                 if (k != j &&
1000                     !memcmp(lgr->lnk[j].peer_gid, lgr->lnk[k].peer_gid,
1001                             SMC_GID_SIZE)) {
1002                         asym_idx = j;
1003                         break;
1004                 }
1005         }
1006 out:
1007         return (asym_idx < 0) ? NULL : &lgr->lnk[asym_idx];
1008 }
1009
1010 static void smc_llc_delete_asym_link(struct smc_link_group *lgr)
1011 {
1012         struct smc_link *lnk_new = NULL, *lnk_asym;
1013         struct smc_llc_qentry *qentry;
1014         int rc;
1015
1016         lnk_asym = smc_llc_find_asym_link(lgr);
1017         if (!lnk_asym)
1018                 return; /* no asymmetric link */
1019         if (!smc_link_downing(&lnk_asym->state))
1020                 return;
1021         lnk_new = smc_switch_conns(lgr, lnk_asym, false);
1022         smc_wr_tx_wait_no_pending_sends(lnk_asym);
1023         if (!lnk_new)
1024                 goto out_free;
1025         /* change flow type from ADD_LINK into DEL_LINK */
1026         lgr->llc_flow_lcl.type = SMC_LLC_FLOW_DEL_LINK;
1027         rc = smc_llc_send_delete_link(lnk_new, lnk_asym->link_id, SMC_LLC_REQ,
1028                                       true, SMC_LLC_DEL_NO_ASYM_NEEDED);
1029         if (rc) {
1030                 smcr_link_down_cond(lnk_new);
1031                 goto out_free;
1032         }
1033         qentry = smc_llc_wait(lgr, lnk_new, SMC_LLC_WAIT_TIME,
1034                               SMC_LLC_DELETE_LINK);
1035         if (!qentry) {
1036                 smcr_link_down_cond(lnk_new);
1037                 goto out_free;
1038         }
1039         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1040 out_free:
1041         smcr_link_clear(lnk_asym, true);
1042 }
1043
1044 static int smc_llc_srv_rkey_exchange(struct smc_link *link,
1045                                      struct smc_link *link_new)
1046 {
1047         struct smc_llc_msg_add_link_cont *addc_llc;
1048         struct smc_link_group *lgr = link->lgr;
1049         u8 max, num_rkeys_send, num_rkeys_recv;
1050         struct smc_llc_qentry *qentry = NULL;
1051         struct smc_buf_desc *buf_pos;
1052         int buf_lst;
1053         int rc = 0;
1054         int i;
1055
1056         mutex_lock(&lgr->rmbs_lock);
1057         num_rkeys_send = lgr->conns_num;
1058         buf_pos = smc_llc_get_first_rmb(lgr, &buf_lst);
1059         do {
1060                 smc_llc_add_link_cont(link, link_new, &num_rkeys_send,
1061                                       &buf_lst, &buf_pos);
1062                 qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_TIME,
1063                                       SMC_LLC_ADD_LINK_CONT);
1064                 if (!qentry) {
1065                         rc = -ETIMEDOUT;
1066                         goto out;
1067                 }
1068                 addc_llc = &qentry->msg.add_link_cont;
1069                 num_rkeys_recv = addc_llc->num_rkeys;
1070                 max = min_t(u8, num_rkeys_recv, SMC_LLC_RKEYS_PER_CONT_MSG);
1071                 for (i = 0; i < max; i++) {
1072                         smc_rtoken_set(lgr, link->link_idx, link_new->link_idx,
1073                                        addc_llc->rt[i].rmb_key,
1074                                        addc_llc->rt[i].rmb_vaddr_new,
1075                                        addc_llc->rt[i].rmb_key_new);
1076                         num_rkeys_recv--;
1077                 }
1078                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1079         } while (num_rkeys_send || num_rkeys_recv);
1080 out:
1081         mutex_unlock(&lgr->rmbs_lock);
1082         return rc;
1083 }
1084
1085 static int smc_llc_srv_conf_link(struct smc_link *link,
1086                                  struct smc_link *link_new,
1087                                  enum smc_lgr_type lgr_new_t)
1088 {
1089         struct smc_link_group *lgr = link->lgr;
1090         struct smc_llc_qentry *qentry = NULL;
1091         int rc;
1092
1093         /* send CONFIRM LINK request over the RoCE fabric */
1094         rc = smc_llc_send_confirm_link(link_new, SMC_LLC_REQ);
1095         if (rc)
1096                 return -ENOLINK;
1097         /* receive CONFIRM LINK response over the RoCE fabric */
1098         qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_FIRST_TIME, 0);
1099         if (!qentry ||
1100             qentry->msg.raw.hdr.common.type != SMC_LLC_CONFIRM_LINK) {
1101                 /* send DELETE LINK */
1102                 smc_llc_send_delete_link(link, link_new->link_id, SMC_LLC_REQ,
1103                                          false, SMC_LLC_DEL_LOST_PATH);
1104                 if (qentry)
1105                         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1106                 return -ENOLINK;
1107         }
1108         smc_llc_save_peer_uid(qentry);
1109         smc_llc_link_active(link_new);
1110         if (lgr_new_t == SMC_LGR_ASYMMETRIC_LOCAL ||
1111             lgr_new_t == SMC_LGR_ASYMMETRIC_PEER)
1112                 smcr_lgr_set_type_asym(lgr, lgr_new_t, link_new->link_idx);
1113         else
1114                 smcr_lgr_set_type(lgr, lgr_new_t);
1115         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1116         return 0;
1117 }
1118
1119 int smc_llc_srv_add_link(struct smc_link *link)
1120 {
1121         enum smc_lgr_type lgr_new_t = SMC_LGR_SYMMETRIC;
1122         struct smc_link_group *lgr = link->lgr;
1123         struct smc_llc_msg_add_link *add_llc;
1124         struct smc_llc_qentry *qentry = NULL;
1125         struct smc_link *link_new;
1126         struct smc_init_info ini;
1127         int lnk_idx, rc = 0;
1128
1129         /* ignore client add link recommendation, start new flow */
1130         ini.vlan_id = lgr->vlan_id;
1131         smc_pnet_find_alt_roce(lgr, &ini, link->smcibdev);
1132         if (!ini.ib_dev) {
1133                 lgr_new_t = SMC_LGR_ASYMMETRIC_LOCAL;
1134                 ini.ib_dev = link->smcibdev;
1135                 ini.ib_port = link->ibport;
1136         }
1137         lnk_idx = smc_llc_alloc_alt_link(lgr, lgr_new_t);
1138         if (lnk_idx < 0)
1139                 return 0;
1140
1141         rc = smcr_link_init(lgr, &lgr->lnk[lnk_idx], lnk_idx, &ini);
1142         if (rc)
1143                 return rc;
1144         link_new = &lgr->lnk[lnk_idx];
1145         rc = smc_llc_send_add_link(link,
1146                                    link_new->smcibdev->mac[ini.ib_port - 1],
1147                                    link_new->gid, link_new, SMC_LLC_REQ);
1148         if (rc)
1149                 goto out_err;
1150         /* receive ADD LINK response over the RoCE fabric */
1151         qentry = smc_llc_wait(lgr, link, SMC_LLC_WAIT_TIME, SMC_LLC_ADD_LINK);
1152         if (!qentry) {
1153                 rc = -ETIMEDOUT;
1154                 goto out_err;
1155         }
1156         add_llc = &qentry->msg.add_link;
1157         if (add_llc->hd.flags & SMC_LLC_FLAG_ADD_LNK_REJ) {
1158                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1159                 rc = -ENOLINK;
1160                 goto out_err;
1161         }
1162         if (lgr->type == SMC_LGR_SINGLE &&
1163             (!memcmp(add_llc->sender_gid, link->peer_gid, SMC_GID_SIZE) &&
1164              !memcmp(add_llc->sender_mac, link->peer_mac, ETH_ALEN))) {
1165                 lgr_new_t = SMC_LGR_ASYMMETRIC_PEER;
1166         }
1167         smc_llc_save_add_link_info(link_new, add_llc);
1168         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1169
1170         rc = smc_ib_ready_link(link_new);
1171         if (rc)
1172                 goto out_err;
1173         rc = smcr_buf_map_lgr(link_new);
1174         if (rc)
1175                 goto out_err;
1176         rc = smcr_buf_reg_lgr(link_new);
1177         if (rc)
1178                 goto out_err;
1179         rc = smc_llc_srv_rkey_exchange(link, link_new);
1180         if (rc)
1181                 goto out_err;
1182         rc = smc_llc_srv_conf_link(link, link_new, lgr_new_t);
1183         if (rc)
1184                 goto out_err;
1185         return 0;
1186 out_err:
1187         smcr_link_clear(link_new, false);
1188         return rc;
1189 }
1190
1191 static void smc_llc_process_srv_add_link(struct smc_link_group *lgr)
1192 {
1193         struct smc_link *link = lgr->llc_flow_lcl.qentry->link;
1194         int rc;
1195
1196         smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1197
1198         mutex_lock(&lgr->llc_conf_mutex);
1199         rc = smc_llc_srv_add_link(link);
1200         if (!rc && lgr->type == SMC_LGR_SYMMETRIC) {
1201                 /* delete any asymmetric link */
1202                 smc_llc_delete_asym_link(lgr);
1203         }
1204         mutex_unlock(&lgr->llc_conf_mutex);
1205 }
1206
1207 /* enqueue a local add_link req to trigger a new add_link flow */
1208 void smc_llc_add_link_local(struct smc_link *link)
1209 {
1210         struct smc_llc_msg_add_link add_llc = {};
1211
1212         add_llc.hd.length = sizeof(add_llc);
1213         add_llc.hd.common.type = SMC_LLC_ADD_LINK;
1214         /* no dev and port needed */
1215         smc_llc_enqueue(link, (union smc_llc_msg *)&add_llc);
1216 }
1217
1218 /* worker to process an add link message */
1219 static void smc_llc_add_link_work(struct work_struct *work)
1220 {
1221         struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1222                                                   llc_add_link_work);
1223
1224         if (list_empty(&lgr->list)) {
1225                 /* link group is terminating */
1226                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1227                 goto out;
1228         }
1229
1230         if (lgr->role == SMC_CLNT)
1231                 smc_llc_process_cli_add_link(lgr);
1232         else
1233                 smc_llc_process_srv_add_link(lgr);
1234 out:
1235         smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1236 }
1237
1238 /* enqueue a local del_link msg to trigger a new del_link flow,
1239  * called only for role SMC_SERV
1240  */
1241 void smc_llc_srv_delete_link_local(struct smc_link *link, u8 del_link_id)
1242 {
1243         struct smc_llc_msg_del_link del_llc = {};
1244
1245         del_llc.hd.length = sizeof(del_llc);
1246         del_llc.hd.common.type = SMC_LLC_DELETE_LINK;
1247         del_llc.link_num = del_link_id;
1248         del_llc.reason = htonl(SMC_LLC_DEL_LOST_PATH);
1249         del_llc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
1250         smc_llc_enqueue(link, (union smc_llc_msg *)&del_llc);
1251 }
1252
1253 static void smc_llc_process_cli_delete_link(struct smc_link_group *lgr)
1254 {
1255         struct smc_link *lnk_del = NULL, *lnk_asym, *lnk;
1256         struct smc_llc_msg_del_link *del_llc;
1257         struct smc_llc_qentry *qentry;
1258         int active_links;
1259         int lnk_idx;
1260
1261         qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1262         lnk = qentry->link;
1263         del_llc = &qentry->msg.delete_link;
1264
1265         if (del_llc->hd.flags & SMC_LLC_FLAG_DEL_LINK_ALL) {
1266                 smc_lgr_terminate_sched(lgr);
1267                 goto out;
1268         }
1269         mutex_lock(&lgr->llc_conf_mutex);
1270         /* delete single link */
1271         for (lnk_idx = 0; lnk_idx < SMC_LINKS_PER_LGR_MAX; lnk_idx++) {
1272                 if (lgr->lnk[lnk_idx].link_id != del_llc->link_num)
1273                         continue;
1274                 lnk_del = &lgr->lnk[lnk_idx];
1275                 break;
1276         }
1277         del_llc->hd.flags |= SMC_LLC_FLAG_RESP;
1278         if (!lnk_del) {
1279                 /* link was not found */
1280                 del_llc->reason = htonl(SMC_LLC_DEL_NOLNK);
1281                 smc_llc_send_message(lnk, &qentry->msg);
1282                 goto out_unlock;
1283         }
1284         lnk_asym = smc_llc_find_asym_link(lgr);
1285
1286         del_llc->reason = 0;
1287         smc_llc_send_message(lnk, &qentry->msg); /* response */
1288
1289         if (smc_link_downing(&lnk_del->state)) {
1290                 if (smc_switch_conns(lgr, lnk_del, false))
1291                         smc_wr_tx_wait_no_pending_sends(lnk_del);
1292         }
1293         smcr_link_clear(lnk_del, true);
1294
1295         active_links = smc_llc_active_link_count(lgr);
1296         if (lnk_del == lnk_asym) {
1297                 /* expected deletion of asym link, don't change lgr state */
1298         } else if (active_links == 1) {
1299                 smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1300         } else if (!active_links) {
1301                 smcr_lgr_set_type(lgr, SMC_LGR_NONE);
1302                 smc_lgr_terminate_sched(lgr);
1303         }
1304 out_unlock:
1305         mutex_unlock(&lgr->llc_conf_mutex);
1306 out:
1307         kfree(qentry);
1308 }
1309
1310 /* try to send a DELETE LINK ALL request on any active link,
1311  * waiting for send completion
1312  */
1313 void smc_llc_send_link_delete_all(struct smc_link_group *lgr, bool ord, u32 rsn)
1314 {
1315         struct smc_llc_msg_del_link delllc = {};
1316         int i;
1317
1318         delllc.hd.common.type = SMC_LLC_DELETE_LINK;
1319         delllc.hd.length = sizeof(delllc);
1320         if (ord)
1321                 delllc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ORDERLY;
1322         delllc.hd.flags |= SMC_LLC_FLAG_DEL_LINK_ALL;
1323         delllc.reason = htonl(rsn);
1324
1325         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1326                 if (!smc_link_usable(&lgr->lnk[i]))
1327                         continue;
1328                 if (!smc_llc_send_message_wait(&lgr->lnk[i], &delllc))
1329                         break;
1330         }
1331 }
1332
1333 static void smc_llc_process_srv_delete_link(struct smc_link_group *lgr)
1334 {
1335         struct smc_llc_msg_del_link *del_llc;
1336         struct smc_link *lnk, *lnk_del;
1337         struct smc_llc_qentry *qentry;
1338         int active_links;
1339         int i;
1340
1341         mutex_lock(&lgr->llc_conf_mutex);
1342         qentry = smc_llc_flow_qentry_clr(&lgr->llc_flow_lcl);
1343         lnk = qentry->link;
1344         del_llc = &qentry->msg.delete_link;
1345
1346         if (qentry->msg.delete_link.hd.flags & SMC_LLC_FLAG_DEL_LINK_ALL) {
1347                 /* delete entire lgr */
1348                 smc_llc_send_link_delete_all(lgr, true, ntohl(
1349                                               qentry->msg.delete_link.reason));
1350                 smc_lgr_terminate_sched(lgr);
1351                 goto out;
1352         }
1353         /* delete single link */
1354         lnk_del = NULL;
1355         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
1356                 if (lgr->lnk[i].link_id == del_llc->link_num) {
1357                         lnk_del = &lgr->lnk[i];
1358                         break;
1359                 }
1360         }
1361         if (!lnk_del)
1362                 goto out; /* asymmetric link already deleted */
1363
1364         if (smc_link_downing(&lnk_del->state)) {
1365                 if (smc_switch_conns(lgr, lnk_del, false))
1366                         smc_wr_tx_wait_no_pending_sends(lnk_del);
1367         }
1368         if (!list_empty(&lgr->list)) {
1369                 /* qentry is either a request from peer (send it back to
1370                  * initiate the DELETE_LINK processing), or a locally
1371                  * enqueued DELETE_LINK request (forward it)
1372                  */
1373                 if (!smc_llc_send_message(lnk, &qentry->msg)) {
1374                         struct smc_llc_qentry *qentry2;
1375
1376                         qentry2 = smc_llc_wait(lgr, lnk, SMC_LLC_WAIT_TIME,
1377                                                SMC_LLC_DELETE_LINK);
1378                         if (qentry2)
1379                                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1380                 }
1381         }
1382         smcr_link_clear(lnk_del, true);
1383
1384         active_links = smc_llc_active_link_count(lgr);
1385         if (active_links == 1) {
1386                 smcr_lgr_set_type(lgr, SMC_LGR_SINGLE);
1387         } else if (!active_links) {
1388                 smcr_lgr_set_type(lgr, SMC_LGR_NONE);
1389                 smc_lgr_terminate_sched(lgr);
1390         }
1391
1392         if (lgr->type == SMC_LGR_SINGLE && !list_empty(&lgr->list)) {
1393                 /* trigger setup of asymm alt link */
1394                 smc_llc_add_link_local(lnk);
1395         }
1396 out:
1397         mutex_unlock(&lgr->llc_conf_mutex);
1398         kfree(qentry);
1399 }
1400
1401 static void smc_llc_delete_link_work(struct work_struct *work)
1402 {
1403         struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1404                                                   llc_del_link_work);
1405
1406         if (list_empty(&lgr->list)) {
1407                 /* link group is terminating */
1408                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1409                 goto out;
1410         }
1411
1412         if (lgr->role == SMC_CLNT)
1413                 smc_llc_process_cli_delete_link(lgr);
1414         else
1415                 smc_llc_process_srv_delete_link(lgr);
1416 out:
1417         smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
1418 }
1419
1420 /* process a confirm_rkey request from peer, remote flow */
1421 static void smc_llc_rmt_conf_rkey(struct smc_link_group *lgr)
1422 {
1423         struct smc_llc_msg_confirm_rkey *llc;
1424         struct smc_llc_qentry *qentry;
1425         struct smc_link *link;
1426         int num_entries;
1427         int rk_idx;
1428         int i;
1429
1430         qentry = lgr->llc_flow_rmt.qentry;
1431         llc = &qentry->msg.confirm_rkey;
1432         link = qentry->link;
1433
1434         num_entries = llc->rtoken[0].num_rkeys;
1435         /* first rkey entry is for receiving link */
1436         rk_idx = smc_rtoken_add(link,
1437                                 llc->rtoken[0].rmb_vaddr,
1438                                 llc->rtoken[0].rmb_key);
1439         if (rk_idx < 0)
1440                 goto out_err;
1441
1442         for (i = 1; i <= min_t(u8, num_entries, SMC_LLC_RKEYS_PER_MSG - 1); i++)
1443                 smc_rtoken_set2(lgr, rk_idx, llc->rtoken[i].link_id,
1444                                 llc->rtoken[i].rmb_vaddr,
1445                                 llc->rtoken[i].rmb_key);
1446         /* max links is 3 so there is no need to support conf_rkey_cont msgs */
1447         goto out;
1448 out_err:
1449         llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1450         llc->hd.flags |= SMC_LLC_FLAG_RKEY_RETRY;
1451 out:
1452         llc->hd.flags |= SMC_LLC_FLAG_RESP;
1453         smc_llc_send_message(link, &qentry->msg);
1454         smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
1455 }
1456
1457 /* process a delete_rkey request from peer, remote flow */
1458 static void smc_llc_rmt_delete_rkey(struct smc_link_group *lgr)
1459 {
1460         struct smc_llc_msg_delete_rkey *llc;
1461         struct smc_llc_qentry *qentry;
1462         struct smc_link *link;
1463         u8 err_mask = 0;
1464         int i, max;
1465
1466         qentry = lgr->llc_flow_rmt.qentry;
1467         llc = &qentry->msg.delete_rkey;
1468         link = qentry->link;
1469
1470         max = min_t(u8, llc->num_rkeys, SMC_LLC_DEL_RKEY_MAX);
1471         for (i = 0; i < max; i++) {
1472                 if (smc_rtoken_delete(link, llc->rkey[i]))
1473                         err_mask |= 1 << (SMC_LLC_DEL_RKEY_MAX - 1 - i);
1474         }
1475         if (err_mask) {
1476                 llc->hd.flags |= SMC_LLC_FLAG_RKEY_NEG;
1477                 llc->err_mask = err_mask;
1478         }
1479         llc->hd.flags |= SMC_LLC_FLAG_RESP;
1480         smc_llc_send_message(link, &qentry->msg);
1481         smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
1482 }
1483
1484 static void smc_llc_protocol_violation(struct smc_link_group *lgr, u8 type)
1485 {
1486         pr_warn_ratelimited("smc: SMC-R lg %*phN LLC protocol violation: "
1487                             "llc_type %d\n", SMC_LGR_ID_SIZE, &lgr->id, type);
1488         smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_PROT_VIOL);
1489         smc_lgr_terminate_sched(lgr);
1490 }
1491
1492 /* flush the llc event queue */
1493 static void smc_llc_event_flush(struct smc_link_group *lgr)
1494 {
1495         struct smc_llc_qentry *qentry, *q;
1496
1497         spin_lock_bh(&lgr->llc_event_q_lock);
1498         list_for_each_entry_safe(qentry, q, &lgr->llc_event_q, list) {
1499                 list_del_init(&qentry->list);
1500                 kfree(qentry);
1501         }
1502         spin_unlock_bh(&lgr->llc_event_q_lock);
1503 }
1504
1505 static void smc_llc_event_handler(struct smc_llc_qentry *qentry)
1506 {
1507         union smc_llc_msg *llc = &qentry->msg;
1508         struct smc_link *link = qentry->link;
1509         struct smc_link_group *lgr = link->lgr;
1510
1511         if (!smc_link_usable(link))
1512                 goto out;
1513
1514         switch (llc->raw.hdr.common.type) {
1515         case SMC_LLC_TEST_LINK:
1516                 llc->test_link.hd.flags |= SMC_LLC_FLAG_RESP;
1517                 smc_llc_send_message(link, llc);
1518                 break;
1519         case SMC_LLC_ADD_LINK:
1520                 if (list_empty(&lgr->list))
1521                         goto out;       /* lgr is terminating */
1522                 if (lgr->role == SMC_CLNT) {
1523                         if (smc_llc_is_local_add_link(llc)) {
1524                                 if (lgr->llc_flow_lcl.type ==
1525                                     SMC_LLC_FLOW_ADD_LINK)
1526                                         break;  /* add_link in progress */
1527                                 if (smc_llc_flow_start(&lgr->llc_flow_lcl,
1528                                                        qentry)) {
1529                                         schedule_work(&lgr->llc_add_link_work);
1530                                 }
1531                                 return;
1532                         }
1533                         if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK &&
1534                             !lgr->llc_flow_lcl.qentry) {
1535                                 /* a flow is waiting for this message */
1536                                 smc_llc_flow_qentry_set(&lgr->llc_flow_lcl,
1537                                                         qentry);
1538                                 wake_up(&lgr->llc_msg_waiter);
1539                         } else if (smc_llc_flow_start(&lgr->llc_flow_lcl,
1540                                                       qentry)) {
1541                                 schedule_work(&lgr->llc_add_link_work);
1542                         }
1543                 } else if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1544                         /* as smc server, handle client suggestion */
1545                         schedule_work(&lgr->llc_add_link_work);
1546                 }
1547                 return;
1548         case SMC_LLC_CONFIRM_LINK:
1549         case SMC_LLC_ADD_LINK_CONT:
1550                 if (lgr->llc_flow_lcl.type != SMC_LLC_FLOW_NONE) {
1551                         /* a flow is waiting for this message */
1552                         smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
1553                         wake_up(&lgr->llc_msg_waiter);
1554                         return;
1555                 }
1556                 break;
1557         case SMC_LLC_DELETE_LINK:
1558                 if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_ADD_LINK &&
1559                     !lgr->llc_flow_lcl.qentry) {
1560                         /* DEL LINK REQ during ADD LINK SEQ */
1561                         smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry);
1562                         wake_up(&lgr->llc_msg_waiter);
1563                 } else if (smc_llc_flow_start(&lgr->llc_flow_lcl, qentry)) {
1564                         schedule_work(&lgr->llc_del_link_work);
1565                 }
1566                 return;
1567         case SMC_LLC_CONFIRM_RKEY:
1568                 /* new request from remote, assign to remote flow */
1569                 if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
1570                         /* process here, does not wait for more llc msgs */
1571                         smc_llc_rmt_conf_rkey(lgr);
1572                         smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
1573                 }
1574                 return;
1575         case SMC_LLC_CONFIRM_RKEY_CONT:
1576                 /* not used because max links is 3, and 3 rkeys fit into
1577                  * one CONFIRM_RKEY message
1578                  */
1579                 break;
1580         case SMC_LLC_DELETE_RKEY:
1581                 /* new request from remote, assign to remote flow */
1582                 if (smc_llc_flow_start(&lgr->llc_flow_rmt, qentry)) {
1583                         /* process here, does not wait for more llc msgs */
1584                         smc_llc_rmt_delete_rkey(lgr);
1585                         smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
1586                 }
1587                 return;
1588         default:
1589                 smc_llc_protocol_violation(lgr, llc->raw.hdr.common.type);
1590                 break;
1591         }
1592 out:
1593         kfree(qentry);
1594 }
1595
1596 /* worker to process llc messages on the event queue */
1597 static void smc_llc_event_work(struct work_struct *work)
1598 {
1599         struct smc_link_group *lgr = container_of(work, struct smc_link_group,
1600                                                   llc_event_work);
1601         struct smc_llc_qentry *qentry;
1602
1603         if (!lgr->llc_flow_lcl.type && lgr->delayed_event) {
1604                 qentry = lgr->delayed_event;
1605                 lgr->delayed_event = NULL;
1606                 if (smc_link_usable(qentry->link))
1607                         smc_llc_event_handler(qentry);
1608                 else
1609                         kfree(qentry);
1610         }
1611
1612 again:
1613         spin_lock_bh(&lgr->llc_event_q_lock);
1614         if (!list_empty(&lgr->llc_event_q)) {
1615                 qentry = list_first_entry(&lgr->llc_event_q,
1616                                           struct smc_llc_qentry, list);
1617                 list_del_init(&qentry->list);
1618                 spin_unlock_bh(&lgr->llc_event_q_lock);
1619                 smc_llc_event_handler(qentry);
1620                 goto again;
1621         }
1622         spin_unlock_bh(&lgr->llc_event_q_lock);
1623 }
1624
1625 /* process llc responses in tasklet context */
1626 static void smc_llc_rx_response(struct smc_link *link,
1627                                 struct smc_llc_qentry *qentry)
1628 {
1629         enum smc_llc_flowtype flowtype = link->lgr->llc_flow_lcl.type;
1630         struct smc_llc_flow *flow = &link->lgr->llc_flow_lcl;
1631         u8 llc_type = qentry->msg.raw.hdr.common.type;
1632
1633         switch (llc_type) {
1634         case SMC_LLC_TEST_LINK:
1635                 if (smc_link_active(link))
1636                         complete(&link->llc_testlink_resp);
1637                 break;
1638         case SMC_LLC_ADD_LINK:
1639         case SMC_LLC_ADD_LINK_CONT:
1640         case SMC_LLC_CONFIRM_LINK:
1641                 if (flowtype != SMC_LLC_FLOW_ADD_LINK || flow->qentry)
1642                         break;  /* drop out-of-flow response */
1643                 goto assign;
1644         case SMC_LLC_DELETE_LINK:
1645                 if (flowtype != SMC_LLC_FLOW_DEL_LINK || flow->qentry)
1646                         break;  /* drop out-of-flow response */
1647                 goto assign;
1648         case SMC_LLC_CONFIRM_RKEY:
1649         case SMC_LLC_DELETE_RKEY:
1650                 if (flowtype != SMC_LLC_FLOW_RKEY || flow->qentry)
1651                         break;  /* drop out-of-flow response */
1652                 goto assign;
1653         case SMC_LLC_CONFIRM_RKEY_CONT:
1654                 /* not used because max links is 3 */
1655                 break;
1656         default:
1657                 smc_llc_protocol_violation(link->lgr, llc_type);
1658                 break;
1659         }
1660         kfree(qentry);
1661         return;
1662 assign:
1663         /* assign responses to the local flow, we requested them */
1664         smc_llc_flow_qentry_set(&link->lgr->llc_flow_lcl, qentry);
1665         wake_up(&link->lgr->llc_msg_waiter);
1666 }
1667
1668 static void smc_llc_enqueue(struct smc_link *link, union smc_llc_msg *llc)
1669 {
1670         struct smc_link_group *lgr = link->lgr;
1671         struct smc_llc_qentry *qentry;
1672         unsigned long flags;
1673
1674         qentry = kmalloc(sizeof(*qentry), GFP_ATOMIC);
1675         if (!qentry)
1676                 return;
1677         qentry->link = link;
1678         INIT_LIST_HEAD(&qentry->list);
1679         memcpy(&qentry->msg, llc, sizeof(union smc_llc_msg));
1680
1681         /* process responses immediately */
1682         if (llc->raw.hdr.flags & SMC_LLC_FLAG_RESP) {
1683                 smc_llc_rx_response(link, qentry);
1684                 return;
1685         }
1686
1687         /* add requests to event queue */
1688         spin_lock_irqsave(&lgr->llc_event_q_lock, flags);
1689         list_add_tail(&qentry->list, &lgr->llc_event_q);
1690         spin_unlock_irqrestore(&lgr->llc_event_q_lock, flags);
1691         queue_work(system_highpri_wq, &lgr->llc_event_work);
1692 }
1693
1694 /* copy received msg and add it to the event queue */
1695 static void smc_llc_rx_handler(struct ib_wc *wc, void *buf)
1696 {
1697         struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
1698         union smc_llc_msg *llc = buf;
1699
1700         if (wc->byte_len < sizeof(*llc))
1701                 return; /* short message */
1702         if (llc->raw.hdr.length != sizeof(*llc))
1703                 return; /* invalid message */
1704
1705         smc_llc_enqueue(link, llc);
1706 }
1707
1708 /***************************** worker, utils *********************************/
1709
1710 static void smc_llc_testlink_work(struct work_struct *work)
1711 {
1712         struct smc_link *link = container_of(to_delayed_work(work),
1713                                              struct smc_link, llc_testlink_wrk);
1714         unsigned long next_interval;
1715         unsigned long expire_time;
1716         u8 user_data[16] = { 0 };
1717         int rc;
1718
1719         if (!smc_link_active(link))
1720                 return;         /* don't reschedule worker */
1721         expire_time = link->wr_rx_tstamp + link->llc_testlink_time;
1722         if (time_is_after_jiffies(expire_time)) {
1723                 next_interval = expire_time - jiffies;
1724                 goto out;
1725         }
1726         reinit_completion(&link->llc_testlink_resp);
1727         smc_llc_send_test_link(link, user_data);
1728         /* receive TEST LINK response over RoCE fabric */
1729         rc = wait_for_completion_interruptible_timeout(&link->llc_testlink_resp,
1730                                                        SMC_LLC_WAIT_TIME);
1731         if (!smc_link_active(link))
1732                 return;         /* link state changed */
1733         if (rc <= 0) {
1734                 smcr_link_down_cond_sched(link);
1735                 return;
1736         }
1737         next_interval = link->llc_testlink_time;
1738 out:
1739         schedule_delayed_work(&link->llc_testlink_wrk, next_interval);
1740 }
1741
1742 void smc_llc_lgr_init(struct smc_link_group *lgr, struct smc_sock *smc)
1743 {
1744         struct net *net = sock_net(smc->clcsock->sk);
1745
1746         INIT_WORK(&lgr->llc_event_work, smc_llc_event_work);
1747         INIT_WORK(&lgr->llc_add_link_work, smc_llc_add_link_work);
1748         INIT_WORK(&lgr->llc_del_link_work, smc_llc_delete_link_work);
1749         INIT_LIST_HEAD(&lgr->llc_event_q);
1750         spin_lock_init(&lgr->llc_event_q_lock);
1751         spin_lock_init(&lgr->llc_flow_lock);
1752         init_waitqueue_head(&lgr->llc_flow_waiter);
1753         init_waitqueue_head(&lgr->llc_msg_waiter);
1754         mutex_init(&lgr->llc_conf_mutex);
1755         lgr->llc_testlink_time = net->ipv4.sysctl_tcp_keepalive_time;
1756 }
1757
1758 /* called after lgr was removed from lgr_list */
1759 void smc_llc_lgr_clear(struct smc_link_group *lgr)
1760 {
1761         smc_llc_event_flush(lgr);
1762         wake_up_all(&lgr->llc_flow_waiter);
1763         wake_up_all(&lgr->llc_msg_waiter);
1764         cancel_work_sync(&lgr->llc_event_work);
1765         cancel_work_sync(&lgr->llc_add_link_work);
1766         cancel_work_sync(&lgr->llc_del_link_work);
1767         if (lgr->delayed_event) {
1768                 kfree(lgr->delayed_event);
1769                 lgr->delayed_event = NULL;
1770         }
1771 }
1772
1773 int smc_llc_link_init(struct smc_link *link)
1774 {
1775         init_completion(&link->llc_testlink_resp);
1776         INIT_DELAYED_WORK(&link->llc_testlink_wrk, smc_llc_testlink_work);
1777         return 0;
1778 }
1779
1780 void smc_llc_link_active(struct smc_link *link)
1781 {
1782         pr_warn_ratelimited("smc: SMC-R lg %*phN link added: id %*phN, "
1783                             "peerid %*phN, ibdev %s, ibport %d\n",
1784                             SMC_LGR_ID_SIZE, &link->lgr->id,
1785                             SMC_LGR_ID_SIZE, &link->link_uid,
1786                             SMC_LGR_ID_SIZE, &link->peer_link_uid,
1787                             link->smcibdev->ibdev->name, link->ibport);
1788         link->state = SMC_LNK_ACTIVE;
1789         if (link->lgr->llc_testlink_time) {
1790                 link->llc_testlink_time = link->lgr->llc_testlink_time * HZ;
1791                 schedule_delayed_work(&link->llc_testlink_wrk,
1792                                       link->llc_testlink_time);
1793         }
1794 }
1795
1796 /* called in worker context */
1797 void smc_llc_link_clear(struct smc_link *link, bool log)
1798 {
1799         if (log)
1800                 pr_warn_ratelimited("smc: SMC-R lg %*phN link removed: id %*phN"
1801                                     ", peerid %*phN, ibdev %s, ibport %d\n",
1802                                     SMC_LGR_ID_SIZE, &link->lgr->id,
1803                                     SMC_LGR_ID_SIZE, &link->link_uid,
1804                                     SMC_LGR_ID_SIZE, &link->peer_link_uid,
1805                                     link->smcibdev->ibdev->name, link->ibport);
1806         complete(&link->llc_testlink_resp);
1807         cancel_delayed_work_sync(&link->llc_testlink_wrk);
1808         smc_wr_wakeup_reg_wait(link);
1809         smc_wr_wakeup_tx_wait(link);
1810 }
1811
1812 /* register a new rtoken at the remote peer (for all links) */
1813 int smc_llc_do_confirm_rkey(struct smc_link *send_link,
1814                             struct smc_buf_desc *rmb_desc)
1815 {
1816         struct smc_link_group *lgr = send_link->lgr;
1817         struct smc_llc_qentry *qentry = NULL;
1818         int rc = 0;
1819
1820         rc = smc_llc_send_confirm_rkey(send_link, rmb_desc);
1821         if (rc)
1822                 goto out;
1823         /* receive CONFIRM RKEY response from server over RoCE fabric */
1824         qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
1825                               SMC_LLC_CONFIRM_RKEY);
1826         if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
1827                 rc = -EFAULT;
1828 out:
1829         if (qentry)
1830                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1831         return rc;
1832 }
1833
1834 /* unregister an rtoken at the remote peer */
1835 int smc_llc_do_delete_rkey(struct smc_link_group *lgr,
1836                            struct smc_buf_desc *rmb_desc)
1837 {
1838         struct smc_llc_qentry *qentry = NULL;
1839         struct smc_link *send_link;
1840         int rc = 0;
1841
1842         send_link = smc_llc_usable_link(lgr);
1843         if (!send_link)
1844                 return -ENOLINK;
1845
1846         /* protected by llc_flow control */
1847         rc = smc_llc_send_delete_rkey(send_link, rmb_desc);
1848         if (rc)
1849                 goto out;
1850         /* receive DELETE RKEY response from server over RoCE fabric */
1851         qentry = smc_llc_wait(lgr, send_link, SMC_LLC_WAIT_TIME,
1852                               SMC_LLC_DELETE_RKEY);
1853         if (!qentry || (qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_RKEY_NEG))
1854                 rc = -EFAULT;
1855 out:
1856         if (qentry)
1857                 smc_llc_flow_qentry_del(&lgr->llc_flow_lcl);
1858         return rc;
1859 }
1860
1861 void smc_llc_link_set_uid(struct smc_link *link)
1862 {
1863         __be32 link_uid;
1864
1865         link_uid = htonl(*((u32 *)link->lgr->id) + link->link_id);
1866         memcpy(link->link_uid, &link_uid, SMC_LGR_ID_SIZE);
1867 }
1868
1869 /* save peers link user id, used for debug purposes */
1870 void smc_llc_save_peer_uid(struct smc_llc_qentry *qentry)
1871 {
1872         memcpy(qentry->link->peer_link_uid, qentry->msg.confirm_link.link_uid,
1873                SMC_LGR_ID_SIZE);
1874 }
1875
1876 /* evaluate confirm link request or response */
1877 int smc_llc_eval_conf_link(struct smc_llc_qentry *qentry,
1878                            enum smc_llc_reqresp type)
1879 {
1880         if (type == SMC_LLC_REQ) {      /* SMC server assigns link_id */
1881                 qentry->link->link_id = qentry->msg.confirm_link.link_num;
1882                 smc_llc_link_set_uid(qentry->link);
1883         }
1884         if (!(qentry->msg.raw.hdr.flags & SMC_LLC_FLAG_NO_RMBE_EYEC))
1885                 return -ENOTSUPP;
1886         return 0;
1887 }
1888
1889 /***************************** init, exit, misc ******************************/
1890
1891 static struct smc_wr_rx_handler smc_llc_rx_handlers[] = {
1892         {
1893                 .handler        = smc_llc_rx_handler,
1894                 .type           = SMC_LLC_CONFIRM_LINK
1895         },
1896         {
1897                 .handler        = smc_llc_rx_handler,
1898                 .type           = SMC_LLC_TEST_LINK
1899         },
1900         {
1901                 .handler        = smc_llc_rx_handler,
1902                 .type           = SMC_LLC_ADD_LINK
1903         },
1904         {
1905                 .handler        = smc_llc_rx_handler,
1906                 .type           = SMC_LLC_ADD_LINK_CONT
1907         },
1908         {
1909                 .handler        = smc_llc_rx_handler,
1910                 .type           = SMC_LLC_DELETE_LINK
1911         },
1912         {
1913                 .handler        = smc_llc_rx_handler,
1914                 .type           = SMC_LLC_CONFIRM_RKEY
1915         },
1916         {
1917                 .handler        = smc_llc_rx_handler,
1918                 .type           = SMC_LLC_CONFIRM_RKEY_CONT
1919         },
1920         {
1921                 .handler        = smc_llc_rx_handler,
1922                 .type           = SMC_LLC_DELETE_RKEY
1923         },
1924         {
1925                 .handler        = NULL,
1926         }
1927 };
1928
1929 int __init smc_llc_init(void)
1930 {
1931         struct smc_wr_rx_handler *handler;
1932         int rc = 0;
1933
1934         for (handler = smc_llc_rx_handlers; handler->handler; handler++) {
1935                 INIT_HLIST_NODE(&handler->list);
1936                 rc = smc_wr_rx_register_handler(handler);
1937                 if (rc)
1938                         break;
1939         }
1940         return rc;
1941 }